RTL-SDR Installation on Ubuntu 18.04

Good day! I am Jenrica from the Philippines and I am currently developing a low-cost SDR ground radio receiver for L/S band satellites. I personally emailed you to ask for your build steps for rtlsdr on gnu radio installation (ubuntu 18.04). I have tried many ways already but I still can't find the rtl-sdr source in the GRC. Your positive response is highly appreciated. Thank you